1. Field of the Invention
The present invention relates to a heat pump, and more particularly, to a heat pump that performance and efficiency can be improved.
2. Description of the Conventional Art
In general, a heat pump is a device which cools or heats an indoor space by performing compression, condensation, expansion, and evaporation process of refrigerant.
Heat pumps are classified into standard air conditioners which have one indoor unit connected to one outdoor unit and multi-type air conditioners which have a plurality of indoor units connected to at least one outdoor unit. Also, heat pumps further comprise a water heater to supply hot water and a heater to heat a floor by using hot water.
The heat pump comprises a compressor, a condenser, an expansion valve and an evaporator. Refrigerant is compressed at the compressor, is condensed at the condenser, and then is expanded at the expansion valve. The expanded refrigerant is evaporated at the evaporator, and then flows into the compressor.
But, the conventional heat pump has a problem that the cooling/heating performance is not sufficient to cool/heat a room, when cooling/heating load such as outdoor temperature is changed. For example, in the cold area, heating performance is extremely reduced. If the existing heat pump is changed into the new heat pump having larger capacity or an extra pump is added to the existing heat pump, it needs high cost and large space for installing.